Oled device encapsulating method and structure, oled device, and display screen

ABSTRACT

An OLED device encapsulating structure used to encapsulate an OLED is disclosed. The OLED device encapsulating structure includes a substrate, a barrier layer formed on the substrate, a surface active layer disposed on the barrier layer, and a buffer layer stacked on the surface active layer. An orthogonal projection of the buffer layer onto the barrier layer may coincide with that of the surface active layer onto the barrier layer. A composite layer may further be stacked on the buffer layer. An OLED device and a display screen are also disclosed.

TECHNICAL FIELD

The present disclosure relates to display technology, and moreparticularly relates to an OLED device encapsulating method, an OLEDdevice encapsulating structure, an OLED device, and a display screen.

BACKGROUND

In the current lighting and display field, an organic light-emittingdiode (OLED) (also known as organic optoelectronic display) features alow starting voltage, thinness, lightweight, self-luminous etc. and hasby virtue of these received increasing and extensive study fordevelopment of lighting products and the panel industry to meet thedemands for low energy consumption, thinness, lightweight, and surfacelight source.

OLED devices are extremely sensitive to water and oxygen. In currentOLED thin-film encapsulating, the common technology is depositingalternately a polymer organic thin-film and an inorganic thin-film ontothe OLED so that the OLED could be encapsulated by stacks of severallayers. To achieve better buffering effects, a buffer layer is formedusing inkjet printing. But there exists a gap among the inkjet printingheads, the time required for film-forming encapsulating is lengthenedand the encapsulating cost is increased.

SUMMARY

It is an object of the disclosure to provide an OLED deviceencapsulating method and an OLED device encapsulating structure, whichcan shorten the film-forming time and reduce the cost.

An OLED device and a display screen are also provided.

The OLED device encapsulating structure of the disclosure is used toencapsulate the OLED layer, and includes a substrate, a barrier layerformed on the substrate, a surface active layer disposed on the barrierlayer, and a buffer layer stacked on the surface active layer. Anorthogonal projection of the buffer layer onto the barrier layer mayalign and coincide with that of the surface active layer onto thebarrier layer. A composite layer may further be stacked on the bufferlayer.

The surface active layer material may be one of a hydrophilic polymeractive material, polyol based salt, or polyol based ethers.

The surface active layer may be formed by inkjet printing.

The composite layer may include a first barrier layer and a first bufferlayer stacked on the first barrier layer, or alternatively a pluralityof first barrier layers and a first buffer layer sandwiched betweenevery two first barrier layers. The first one of the plurality of firstbarrier layers may be in contact with the buffer layer.

The OLED device encapsulating method of this disclosure is used toencapsulate an OLED. The method includes the follows.

A substrate that covers the OLED is provided and a barrier layer isformed on the substrate.

A surface active layer composed of a plurality of strips arranged in theform of a matrix is formed on the barrier layer by inkjet printing.

Buffer strips in one-to-one correspondence with the plurality of stripsare sprayed on the surface active layer.

The corresponding buffer strips of the plurality of strips are leftstanding to diffuse and overspread the substrate and further cover thebarrier layer, to form a buffer layer.

The surface active layer may have a thickness in the range of less than100 microns.

The surface active layer material may be one of a hydrophilic polymeractive material, polyol based salt, or polyol based ethers.

The OLED device encapsulating method may further include the follows.The substrate is heated to remove the surface active layer.

The OLED device according to the disclosure may include the OLED deviceencapsulating structure.

The display screen according to the disclosure may include the OLEDdevice.

According to the OLED device encapsulating method of the disclosure, thesurface active layer is formed on the barrier layer, and then the buffermaterial is sprayed to diffuse and cover the entire barrier layer beforethe buffer layer is formed, through the chemical reaction of the surfaceactive layer and the buffer material. Thus, the film-forming time isshortened and the cost is reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to better illustrate the technical solutions embodied by theembodiments of the disclosure or by the prior art, the accompanyingdrawings for use with description of the embodiments or the prior artare briefly described below. It will be apparent that the drawingsdescribed in the following represent merely some embodiments of thedisclosure, and that those of ordinary skill in the art will be able toobtain other drawings from these drawings without performing anycreative work.

FIG. 1 is a schematic diagram of an OLED device encapsulating structureaccording to an embodiment of the disclosure.

FIG. 2 is a schematic diagram of an OLED device encapsulating structureaccording to another embodiment of the disclosure.

FIG. 3 shows a flow chart of an OLED device encapsulating methodaccording to an embodiment of the disclosure.

FIG. 4 is a schematic diagram of forming the surface active layer in theOLED device encapsulating method according to an embodiment of thedisclosure.

FIG. 5 is a schematic diagram of an OLED device according to anembodiment of the disclosure.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

Hereinafter, technical solutions embodied by the embodiments of thedisclosure will be described in a clear and comprehensive manner inreference to the accompanying drawings intended for the embodiments. Itis evident that the embodiments described herein constitute merely somerather than all of the embodiments of the disclosure, and that those ofordinary skill in the art will be able to derive other embodiments basedon these embodiments without making inventive efforts, which all suchderived embodiments shall all fall in the protection scope of thedisclosure.

Referring to FIG. 1, an exemplary embodiment of the disclosure providesan OLED device encapsulating structure 100, used to encapsulate an OLEDlayer. OLED device encapsulating structure 100 may include a substrate10, a barrier layer 11 formed on substrate 10, a surface active layer 12disposed on barrier layer 11, and a buffer layer 13 stacked on surfaceactive layer 12. An orthogonal projection of buffer layer 13 ontobarrier layer 11 may align and coincide with that of surface activelayer 12 onto barrier layer 11. In this embodiment, surface active layer12 material may be one of a hydrophilic polymer active material, polyolbased salt, or polyol based ethers. As long as surface active layer 12material has a free hydroxyl group or H+ that can create a hydrogen bondwith the hydroxyl group and H+ of buffer layer 13 to enhance theirbonding ability, this material will suffice the purpose of thedisclosure. That is, after being sprayed, the buffer material could bediffused by bonding with surface active layer 12 thus forming bufferlayer 13.

If the temperature of the OLED device encapsulating structure isincreased by heating in its manufacturing process, or the OLED device isable to gain sufficient temperature in use, then surface active layer 12will volatilize, without affecting the encapsulating effect. In thisembodiment, surface active layer 12 is formed by inkjet printing.

A composite layer 14 may further be stacked onto buffer layer 13. Inthis embodiment, composite layer 14 includes a first barrier layer 141and a first buffer layer 142 stacked on first barrier layer 141. Barrierlayer 11 and first barrier layer 141 may be made of an inorganicmaterial. Buffer layer 13 and first buffer layer 142 may be of anorganic material.

Referring now to FIG. 2, composite layer 14 may alternatively include aplurality of first barrier layers 141 and a first buffer layer 142sandwiched between every two first barrier layers 141. The first one ofthe plurality of first barrier layers 141 may be in contact with bufferlayer 13. According to actual requirements, a thin-film encapsulatinglayer of an alternate organic layer and inorganic layer structure can bedeposited on the substrate to effect the insulation from water andoxygen and effectively extend the folding and curling lifetime.

Referring now to FIG. 3, the OLED device encapsulating method providedby the disclosure is used to encapsulate an OLED layer and may includethe following steps.

In S1, referring also to FIG. 1, a substrate 10 is provided that coversthe OLED and a barrier layer 11 is then formed on the substrate 10.Barrier layer 11 may be formed by vacuum deposition.

In S2, referring also to FIG. 4, inkjet printing may be used to form onbarrier layer 11 a surface active layer 12 that may be composed of aplurality of strips 120 arranged in the form of a matrix. Surface activelayer 12 may have a thickness in the range of less than 100 microns.Surface active layer 12 material may be one of a hydrophilic polymeractive material, polyol based salt, or polyol based ethers.Specifically, surface active layer 12 may be formed by inkjet printingas a plurality of strips arranged on the surface and evenly spaced fromeach other.

In S3, buffer strips 131 that are in one-to-one correspondence with theplurality of strips of the surface active layer is sprayed onto surfaceactive layer 12. Buffer strips 131 may be formed by inkjet printing,formation (such as manner or path) of the buffer strips may be the sameas the surface active layer 12 is formed.

In S4, the corresponding buffer strips 131 of the plurality of strips,after standing, may overspread the substrate by diffusion and cover thebarrier layer, to form a buffer layer 13.

The inkjet-printed buffer material generally overspreads the entiredevice in a static leveling manner, to achieve the purpose of coveringand encapsulating. By comparison, in this disclosure surface activelayer 12 is first firmed on the barrier layer and then the buffermaterial is sprayed so that the buffer material will diffuse and spreadover the entire barrier layer to form buffer layer 13 through thechemical reaction of surface active layer 12 and the buffer material,thus shortening the film-forming time and reducing the cost.

The method may further include a step S5 in which a composite layer 14is formed on buffer layer 13. Specifically, a first barrier layer may bedeposited onto the barrier layer, and a first buffer layer may then bedeposited onto the first barrier layer.

In this embodiment, barrier layer 11 may be made of an inorganicmaterial, including but not limited to, Al₂O₃, SiN_(x), TiO₂, SiO_(x),which may be used to form the barrier layer using a method including butnot limited to plasma enhanced chemical vapor deposition (PECVD).

Buffer layer 13 may be of a polymeric material, including, but notlimited to, Plasma Polymerized HMDSO (pp-HMDSO (Hexamethyl-dimethylsilyl (HMDSO)), polyacrylates, polycarbonates, polystyrenes and othertransparent polymers, which may be used to form a stress layer toalleviate the stress in the barrier layer.

Referring now FIG. 5, an OLED device is provided that includes OLEDdevice encapsulating structure 100 and an OLED 200. Adopting theencapsulating structure described above, the OLED can save theencapsulating cost. A display incorporating the OLED device is furtherprovided.

While the disclosure has been described above in detail in reference tosome exemplary embodiments, the scope of the disclosure is not limitedthereto. As will occur to those of ordinary skill in the art that all orpart of the embodiments described above as well as the equivalentsubstitutes of the appended claims shall all fall in the scope of thedisclosure.

1. An organic light emitting diode (OLED) device encapsulating structureconfigured to encapsulate an OLED, comprising: a substrate; a barrierlayer formed on the substrate; a surface active layer disposed on thebarrier layer; a buffer layer stacked on the surface active layer, anorthogonal projection of the buffer layer onto the barrier layercoinciding with that of the surface active layer onto the barrier layer;and a composite layer stacked on the buffer layer.
 2. The OLED deviceencapsulating structure of claim 1, wherein the surface active layer isof one of a hydrophilic polymer active material, polyol based salt, orpolyol based ethers.
 3. The OLED device encapsulating structure of claim2, wherein the surface active layer is formed by inkjet printing.
 4. TheOLED device encapsulating structure of claim 1, wherein the compositelayer comprises a first barrier layer and a first buffer layer stackedon the first barrier layer, or a plurality of first barrier layers and afirst buffer layer sandwiched between every two first barrier layers, afirst one of the plurality of first barrier layers contacting the bufferlayer.
 5. An OLED device encapsulating method configured to encapsulatean OLED, comprising: providing a substrate that covers an OLED andforming a barrier layer on the substrate; forming on the barrier layerby inkjet printing a surface active layer composed of a plurality ofstrips arranged in the form of a matrix; spraying on the surface activelayer buffer strips, wherein the buffer stripes are in one-to-onecorrespondence with the plurality of strips of the surface active layer;and standing the corresponding buffer strips of the plurality of stripsto diffuse and overspread the substrate and further cover the barrierlayer to form a buffer layer.
 6. The OLED device encapsulating method ofclaim 5, wherein the surface active layer has a thickness in the rangeof less than 100 microns.
 7. The OLED device encapsulating method ofclaim 5, wherein the surface active layer is of one of a hydrophilicpolymer active material, polyol based salt, or polyol based ethers. 8.The OLED device encapsulating method of claim 5, further comprising,heating the substrate to remove the surface active layer.
 9. An OLEDdevice comprising an OLED device encapsulating structure, the OLEDdevice encapsulating structure being configured to encapsulate an OLEDand comprising: a substrate; a barrier layer formed on the substrate; asurface active layer disposed on the barrier layer; a buffer layerstacked on the surface active layer, an orthogonal projection of thebuffer layer onto the barrier layer coinciding with that of the surfaceactive layer onto the barrier layer; and a composite layer stacked onthe buffer layer.
 10. The OLED device of claim 9, wherein the surfaceactive layer is of one of a hydrophilic polymer active material, polyolbased salt, or polyol based ethers.
 11. The OLED device of claim 10,wherein the surface active layer is formed by inkjet printing.
 12. TheOLED device of claim 9, wherein the composite layer comprises a firstbarrier layer and a first buffer layer stacked on the first barrierlayer, or a plurality of first barrier layers and a first buffer layersandwiched between every two first barrier layers, a first one of theplurality of first barrier layers contacting the buffer layer. 13.(canceled)
 14. The OLED device of claim 12, wherein the barrier layerand the first barrier layer are made of an inorganic material.
 15. TheOLED device of claim 12, wherein the buffer layer and the first bufferlayer are made of an organic material.
 16. The OLED device of claim 9,wherein the buffer layer is made of polymeric material.
 17. The OLEDdevice encapsulating method of claim 5, wherein the buffer stripes areformed in the same manner as the surface active layer.
 18. The OLEDdevice encapsulating structure of claim 4, wherein the barrier layer andthe first barrier layer are made of an inorganic material.
 19. The OLEDdevice encapsulating structure of claim 4, wherein the buffer layer andthe first buffer layer are made of an organic material.
 20. The OLEDdevice encapsulating structure of claim 1, wherein the buffer layer ismade of polymeric material.